There are presently two primary classes of devices for semiconductor wafer processing: batch furnaces and rapid thermal processors (RTP). Batch furnaces process large numbers of wafer at a time, but throughput can still be limited by long temperature ramp up and cool down times which can also reduce processing precision because of their large thermal budget. Newer, fast ramp batch furnaces provided limited improvement. Batch furnaces are also very expensive both in terms of running costs and clean room footprint. Rapid thermal processors (RTP) are fast and have a more advantageous thermal budget, but can only process a single wafer at a time.